A vehicular lamp is provided with, for example, a light source unit that is detachable from a housing outside a lamp that is configured with a lamp body and a cover, and a light emitting element such as, for example, a light emitting diode may be used as a light source of the light source unit.
As for the light source unit, a heat sink formed of a metal material and a resin-molded unit formed of a resin material may be integrally formed by, for example, insert molding (see, e.g., Japanese Patent Laid-open Publication No. 2015-164121). In the light source unit disclosed in Japanese Patent Laid-open Publication No. 2015-164121, the resin-molded unit is called a socket.
A board on which a light emitting element is mounted is attached to a heat sink, the heat generated when the light emitting element is emitted is transferred to the heat sink, and the temperature rise of the light emitting element and the board is suppressed to secure a good light emitting state of the light emitting element.